提示：点击例句中的单词，就可以看到词义解释

Russia toughens stance on energy prices .

俄罗斯在能源价格上立场强硬。

A pummelling toughens you up , makes you fitter for the next engagement .

打击令你坚强，让你更加胜任下一场战斗。

Salt is included in the dough because it regulates the rate of fermentation , toughens the gluten , and prevents the bread from being insipid in taste .

面团中还掺进了盐，因为盐可以调节发酵速率，韧化面筋，防止面包味道变淡。